ssl_smtp_example.go

package main

import (
	"crypto/tls"
	"fmt"
	"github.com/jpoehls/gophermail"
	"log"
	"net"
	"net/smtp"
)

func main() {
	m := &gophermail.Message{}
	m.SetFrom("Domain Sender <[email protected]>")
	m.AddTo("First person <[email protected]>")
	m.AddCc("Second person <[email protected]>")

	message, err = m.Bytes()
	if err != nil {
		log.Panic(err)
	}

	// Connect to the SMTP Server
	servername := "smtp.example.tld:465"

	host, _, _ := net.SplitHostPort(servername)

	auth := smtp.PlainAuth("", "[email protected]", "password", host)

	// TLS config
	tlsconfig := &tls.Config{
		InsecureSkipVerify: true,
		ServerName:         host,
	}

	// Here is the key, you need to call tls.Dial instead of smtp.Dial
	// for smtp servers running on 465 that require an ssl connection
	// from the very beginning (no starttls)
	conn, err := tls.Dial("tcp", servername, tlsconfig)
	if err != nil {
		log.Panic(err)
	}

	c, err := smtp.NewClient(conn, host)
	if err != nil {
		log.Panic(err)
	}

	// Auth
	if err = c.Auth(auth); err != nil {
		log.Panic(err)
	}

	// To && From
	if err = c.Mail(from.Address); err != nil {
		log.Panic(err)
	}

	for _, recipient := range m.To {
		if err = c.Rcpt(recipient.Address); err != nil {
			log.Panic(err)
		}
	}
	for _, recipient := range m.Cc {
		if err = c.Rcpt(recipient.Address); err != nil {
			log.Panic(err)
		}
	}
	for _, recipient := range m.Bcc {
		if err = c.Rcpt(recipient.Address); err != nil {
			log.Panic(err)
		}
	}

	// Data
	w, err := c.Data()
	if err != nil {
		log.Panic(err)
	}

	_, err = w.Write(message)
	if err != nil {
		log.Panic(err)
	}

	err = w.Close()
	if err != nil {
		log.Panic(err)
	}

	c.Quit()

}

// Credit: https://gist.github.com/chrisgillis/10888032